Medium Risk

file_upload

Upload file(s) to a file input element. Provide ref or CSS selector to identify the <input type='file'>, and absolute path(s) to the file(s).

Accepts file system path (path)

Part of the Chrome MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.

@silbercue/chrome Write Risk 3/5

AI agents use file_upload to create or modify resources in Chrome. Write operations carry medium risk because an autonomous agent could trigger bulk unintended modifications. Rate limits prevent a single agent session from making hundreds of changes in rapid succession. Argument validation ensures the agent passes expected values.

Without a policy, an AI agent could call file_upload repeatedly, creating or modifying resources faster than any human could review. Intercept's rate limiting ensures write operations happen at a controlled pace, and argument validation catches malformed or unexpected inputs before they reach Chrome.

Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.

chrome.yaml
tools:
  file_upload:
    rules:
      - action: allow
        rate_limit:
          max: 30
          window: 60

See the full Chrome policy for all 23 tools.

Tool Name file_upload
Category Write
MCP Server Chrome MCP Server
Risk Level Medium

View all 23 tools →

Agents calling write-class tools like file_upload have been implicated in these attack patterns. Read the full case and prevention policy for each:

Browse the full MCP Attack Database →

Other tools in the Write risk category across the catalogue. The same policy patterns (rate-limit, validate) apply to each.

What does the file_upload tool do? +

Upload file(s) to a file input element. Provide ref or CSS selector to identify the <input type='file'>, and absolute path(s) to the file(s).. It is categorised as a Write tool in the Chrome MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on file_upload? +

Add a rule in your Intercept YAML policy under the tools section for file_upload. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the Chrome MCP server.

What risk level is file_upload? +

file_upload is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit file_upload? +

Yes. Add a rate_limit block to the file_upload rule in your Intercept policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block file_upload completely? +

Set action: deny in the Intercept policy for file_upload. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides file_upload? +

file_upload is provided by the Chrome MCP server (@silbercue/chrome). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policies on Chrome

Open source. One binary. Zero dependencies.

npx -y @policylayer/intercept
github.com/policylayer/intercept →
// GET IN TOUCH

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